Synergistic Extraction of Cd, Cu and Ni with D2EHPA/TBP: Screening of Factors by Fractional Factorial Design

Abstract

This work aimed to determine the significant factors that provide great impacts on the efficiency of synergistic extraction of Cd, Cu and Ni from mixed synthetic aqueous solutions with mixture of extractants, di-(2-ethylhexyl) phosphoric acid (D2EHPA) and tributyl phosphate (TBP) by using two-level fractional factorial design. Six factors affecting the synergistic extraction consisted of mixing time (t), concentration of D2EHPA [D2EHPA], concentration of TBP [TBP], concentration of sodium sulphate [Na2SO4], equilibrium pH (pHeq) and organic to aqueous ratio (O:A) were examined. Results from the application of 2 6-1 fractional factorial design showed that [D2EHPA], O:A and interaction of D2EHPA with TBP ([D2EHPA] × [TBP]) have significantly influenced the extraction percentage (E%) for Cd and Cu.